DURATION OF REHABILITATION THERAPY TO ACHIEVE A MINIMAL CLINICALLY IMPORTANT DIFFERENCE IN MOBILITY, WALKING ENDURANCE AND PATIENT-REPORTED PHYSICAL HEALTH: AN OBSERVATIONAL STUDY

OBJECTIVE: To compare the duration of exercise therapy needed to achieve a minimal clinically important difference in mobility, walking endurance and patient-reported global physical health in patients referred for inpatient rehabilitation after knee surgery, hip surgery, or with multiple sclerosis or Parkinson’s disease. DESIGN: Retrospective pre-post intervention observational cohort study. SUBJECTS: A total of 388 patients (57% women, mean age 65.6 years (standard deviation 9.5)) with a minimum length of stay 10 days were included between 1 January 2020 and 30 April 2021. METHODS: Outcomes were assessed at the start of, and discharge from, rehabilitation, using the following measures: mobility (Timed Up and Go test), walking endurance (6-minute walk test), patient-reported global physical health (Global Physical Health subscale of the 10-item Patient-Reported Outcomes Measurement Information System). The duration of exercise therapy needed to achieve a minimal clinically important difference was determined using anchor-based and distribution-based methods. RESULTS: The duration of therapy needed to achieve a minimal clinically important difference was longer in patients with multiple sclerosis or Parkinson’s disease (18–88 h) than in patients after knee or hip surgery (8–25 h). In all patient groups, the duration of exercise therapy needed, determined using the distribution-based method, was shortest for patient-reported global physical health (knee surgery 9.6 h, hip surgery 6.8 h, multiple sclerosis 38.7 h, Parkinson’s disease 18.4 h). CONCLUSION: The duration of active therapies required to achieve a minimal clinically important difference in physical outcomes varies widely (range 8–88 h) among different patient groups and outcomes. LAY ABSTRACT This study in an inpatient rehabilitation setting evaluated the duration of exercise therapy needed to achieve a clinically important difference in 3 outcome measures: mobility, walking endurance, and patient-reported global physical health. Results were compared between 4 groups: patients who had undergone knee surgery; patients who had undergone hip surgery; patients with multiple sclerosis; and those with Parkinson’s disease. The exercise duration required ranged from 8 to 88 h and was longer in patients with multiple sclerosis or Parkinson’s disease, which are chronic progressive neurological conditions, compared with patients who had had knee or hip surgery. In all groups, the duration of exercise therapy required to achieve a clinically important difference was shortest for patient-reported global physical health compared with mobility and walking endurance.